<?php

/**
 * Indicates that a module has not been installed yet.
 */
define('SCHEMA_UNINSTALLED', -1);

/**
 * Indicates that a module has been installed.
 */
define('SCHEMA_INSTALLED', 0);

/**
 * Requirement severity -- Informational message only.
 */
define('REQUIREMENT_INFO', -1);

/**
 * Requirement severity -- Requirement successfully met.
 */
define('REQUIREMENT_OK', 0);

/**
 * Requirement severity -- Warning condition; proceed but flag warning.
 */
define('REQUIREMENT_WARNING', 1);

/**
 * Requirement severity -- Error condition; abort installation.
 */
define('REQUIREMENT_ERROR', 2);

/**
 * File permission check -- File exists.
 */
define('FILE_EXIST', 1);

/**
 * File permission check -- File is readable.
 */
define('FILE_READABLE', 2);

/**
 * File permission check -- File is writable.
 */
define('FILE_WRITABLE', 4);

/**
 * File permission check -- File is executable.
 */
define('FILE_EXECUTABLE', 8);

/**
 * File permission check -- File does not exist.
 */
define('FILE_NOT_EXIST', 16);

/**
 * File permission check -- File is not readable.
 */
define('FILE_NOT_READABLE', 32);

/**
 * File permission check -- File is not writable.
 */
define('FILE_NOT_WRITABLE', 64);

/**
 * File permission check -- File is not executable.
 */
define('FILE_NOT_EXECUTABLE', 128);

/**
 * Initialize the update system by loading all installed module's .install files.
 */
function drupal_load_updates() {
	foreach (drupal_get_installed_schema_version(NULL, FALSE, TRUE) as $module => $schema_version) {
		if ($schema_version > -1) {
			module_load_install($module);
		}
	}
}

/**
 * Returns an array of available schema versions for a module.
 *
 * @param $module
 *   A module name.
 * @return
 *   If the module has updates, an array of available updates sorted by version.
 *   Otherwise, FALSE.
 */
function drupal_get_schema_versions($module) {
	$updates = &drupal_static(__FUNCTION__, NULL);
	if (!isset($updates[$module])) {
		$updates = array();

		foreach (module_list() as $loaded_module) {
			$updates[$loaded_module] = array();
		}

		// Prepare regular expression to match all possible defined hook_update_N().
		$regexp = '/^(?P<module>.+)_update_(?P<version>\d+)$/';
		$functions = get_defined_functions();
		// Narrow this down to functions ending with an integer, since all
		// hook_update_N() functions end this way, and there are other
		// possible functions which match '_update_'. We use preg_grep() here
		// instead of foreaching through all defined functions, since the loop
		// through all PHP functions can take significant page execution time
		// and this function is called on every administrative page via
		// system_requirements().
		foreach (preg_grep('/_\d+$/', $functions['user']) as $function) {
			// If this function is a module update function, add it to the list of
			// module updates.
			if (preg_match($regexp, $function, $matches)) {
				$updates[$matches['module']][] = $matches['version'];
			}
		}
		// Ensure that updates are applied in numerical order.
		foreach ($updates as &$module_updates) {
			sort($module_updates, SORT_NUMERIC);
		}
	}
	return empty($updates[$module]) ? FALSE : $updates[$module];
}

/**
 * Returns the currently installed schema version for a module.
 *
 * @param $module
 *   A module name.
 * @param $reset
 *   Set to TRUE after modifying the system table.
 * @param $array
 *   Set to TRUE if you want to get information about all modules in the
 *   system.
 * @return
 *   The currently installed schema version, or SCHEMA_UNINSTALLED if the
 *   module is not installed.
 */
function drupal_get_installed_schema_version($module, $reset = FALSE, $array = FALSE) {
	static $versions = array();

	if ($reset) {
		$versions = array();
	}

	if (!$versions) {
		$versions = array();
		$result = db_query("SELECT name, schema_version FROM {system} WHERE type = :type", array(':type' => 'module'));
		foreach ($result as $row) {
			$versions[$row->name] = $row->schema_version;
		}
	}

	if ($array) {
		return $versions;
	}
	else {
		return isset($versions[$module]) ? $versions[$module] : SCHEMA_UNINSTALLED;
	}
}

/**
 * Update the installed version information for a module.
 *
 * @param $module
 *   A module name.
 * @param $version
 *   The new schema version.
 */
function drupal_set_installed_schema_version($module, $version) {
	db_update('system')
	->fields(array('schema_version' => $version))
	->condition('name', $module)
	->execute();

	// Reset the static cache of module schema versions.
	drupal_get_installed_schema_version(NULL, TRUE);
}

/**
 * Loads the install profile, extracting its defined distribution name.
 *
 * @return
 *   The distribution name defined in the profile's .info file. Defaults to
 *   "Drupal" if none is explicitly provided by the install profile.
 *
 * @see install_profile_info()
 */
function drupal_install_profile_distribution_name() {
	// During installation, the profile information is stored in the global
	// installation state (it might not be saved anywhere yet).
	if (drupal_installation_attempted()) {
		global $install_state;
		return $install_state['profile_info']['distribution_name'];
	}
	// At all other times, we load the profile via standard methods.
	else {
		$profile = drupal_get_profile();
		$info = system_get_info('module', $profile);
		return $info['distribution_name'];
	}
}

/**
 * Auto detect the base_url with PHP predefined variables.
 *
 * @param $file
 *   The name of the file calling this function so we can strip it out of
 *   the URI when generating the base_url.
 * @return
 *   The auto-detected $base_url that should be configured in settings.php
 */
function drupal_detect_baseurl($file = 'install.php') {
	$proto = $_SERVER['HTTPS'] ? 'https://' : 'http://';
	$host = $_SERVER['SERVER_NAME'];
	$port = ($_SERVER['SERVER_PORT'] == 80 ? '' : ':' . $_SERVER['SERVER_PORT']);
	$uri = preg_replace("/\?.*/", '', $_SERVER['REQUEST_URI']);
	$dir = str_replace("/$file", '', $uri);

	return "$proto$host$port$dir";
}

/**
 * Detect all supported databases that are compiled into PHP.
 *
 * @return
 *  An array of database types compiled into PHP.
 */
function drupal_detect_database_types() {
	$databases = drupal_get_database_types();

	foreach ($databases as $driver => $installer) {
		$databases[$driver] = $installer->name();
	}

	return $databases;
}

/**
 * Return all supported database installer objects that are compiled into PHP.
 *
 * @return
 *  An array of database installer objects compiled into PHP.
 */
function drupal_get_database_types() {
	$databases = array();

	// We define a driver as a directory in /includes/database that in turn
	// contains a database.inc file. That allows us to drop in additional drivers
	// without modifying the installer.
	// Because we have no registry yet, we need to also include the install.inc
	// file for the driver explicitly.
	require_once DRUPAL_ROOT . '/includes/database/database.inc';
	foreach (file_scan_directory(DRUPAL_ROOT . '/includes/database', '/^[a-z]*$/i', array('recurse' => FALSE)) as $file) {
		if (file_exists($file->uri . '/database.inc') && file_exists($file->uri . '/install.inc')) {
			$drivers[$file->filename] = $file->uri;
		}
	}

	foreach ($drivers as $driver => $file) {
		$installer = db_installer_object($driver);
		if ($installer->installable()) {
			$databases[$driver] = $installer;
		}
	}

	// Usability: unconditionally put the MySQL driver on top.
	if (isset($databases['mysql'])) {
		$mysql_database = $databases['mysql'];
		unset($databases['mysql']);
		$databases = array('mysql' => $mysql_database) + $databases;
	}

	return $databases;
}

/**
 * Database installer structure.
 *
 * Defines basic Drupal requirements for databases.
 */
abstract class DatabaseTasks {

	/**
	 * Structure that describes each task to run.
	 *
	 * @var array
	 *
	 * Each value of the tasks array is an associative array defining the function
	 * to call (optional) and any arguments to be passed to the function.
	 */
	protected $tasks = array(
			array(
					'function'    => 'checkEngineVersion',
					'arguments'   => array(),
			),
			array(
					'arguments'   => array(
							'CREATE TABLE {drupal_install_test} (id int NULL)',
							'Drupal can use CREATE TABLE database commands.',
							'Failed to <strong>CREATE</strong> a test table on your database server with the command %query. The server reports the following message: %error.<p>Are you sure the configured username has the necessary permissions to create tables in the database?</p>',
							TRUE,
					),
			),
			array(
					'arguments'   => array(
							'INSERT INTO {drupal_install_test} (id) VALUES (1)',
							'Drupal can use INSERT database commands.',
							'Failed to <strong>INSERT</strong> a value into a test table on your database server. We tried inserting a value with the command %query and the server reported the following error: %error.',
							),
							),
							array(
							'arguments'   => array(
							'UPDATE {drupal_install_test} SET id = 2',
							'Drupal can use UPDATE database commands.',
							'Failed to <strong>UPDATE</strong> a value in a test table on your database server. We tried updating a value with the command %query and the server reported the following error: %error.',
							),
							),
							array(
							'arguments'   => array(
							'DELETE FROM {drupal_install_test}',
							'Drupal can use DELETE database commands.',
							'Failed to <strong>DELETE</strong> a value from a test table on your database server. We tried deleting a value with the command %query and the server reported the following error: %error.',
							),
							),
							array(
							'arguments'   => array(
							'DROP TABLE {drupal_install_test}',
							'Drupal can use DROP TABLE database commands.',
							'Failed to <strong>DROP</strong> a test table from your database server. We tried dropping a table with the command %query and the server reported the following error %error.',
							),
							),
							);

							/**
							 * Results from tasks.
							 *
							 * @var array
							 */
							protected $results = array();

							/**
							 * Ensure the PDO driver is supported by the version of PHP in use.
							 */
							protected function hasPdoDriver() {
								return in_array($this->pdoDriver, PDO::getAvailableDrivers());
							}

							/**
							 * Assert test as failed.
							 */
							protected function fail($message) {
								$this->results[$message] = FALSE;
							}

							/**
							 * Assert test as a pass.
							 */
							protected function pass($message) {
								$this->results[$message] = TRUE;
							}

							/**
							 * Check whether Drupal is installable on the database.
							 */
							public function installable() {
								return $this->hasPdoDriver() && empty($this->error);
							}

							/**
							 * Return the human-readable name of the driver.
							 */
							abstract public function name();

							/**
							 * Return the minimum required version of the engine.
							 *
							 * @return
							 *   A version string. If not NULL, it will be checked against the version
							 *   reported by the Database engine using version_compare().
							 */
							public function minimumVersion() {
								return NULL;
							}

							/**
							 * Run database tasks and tests to see if Drupal can run on the database.
							 */
							public function runTasks() {
								// We need to establish a connection before we can run tests.
								if ($this->connect()) {
									foreach ($this->tasks as $task) {
										if (!isset($task['function'])) {
											$task['function'] = 'runTestQuery';
										}
										if (method_exists($this, $task['function'])) {
											// Returning false is fatal. No other tasks can run.
											if (FALSE === call_user_func_array(array($this, $task['function']), $task['arguments'])) {
												break;
											}
										}
										else {
											throw new DatabaseTaskException(st("Failed to run all tasks against the database server. The task %task wasn't found.", array('%task' => $task['function'])));
										}
									}
								}
								// Check for failed results and compile message
								$message = '';
								foreach ($this->results as $result => $success) {
									if (!$success) {
										$message .= '<p class="error">' . $result  . '</p>';
									}
								}
								if (!empty($message)) {
									$message = '<p>In order for Drupal to work, and to continue with the installation process, you must resolve all issues reported below. For more help with configuring your database server, see the <a href="http://drupal.org/getting-started/install">installation handbook</a>. If you are unsure what any of this means you should probably contact your hosting provider.</p>' . $message;
									throw new DatabaseTaskException($message);
								}
							}

							/**
							 * Check if we can connect to the database.
							 */
							protected function connect() {
								try {
									// This doesn't actually test the connection.
									db_set_active();
									// Now actually do a check.
									Database::getConnection();
									$this->pass('Drupal can CONNECT to the database ok.');
								}
								catch (Exception $e) {
									$this->fail(st('Failed to connect to your database server. The server reports the following message: %error.<ul><li>Is the database server running?</li><li>Does the database exist, and have you entered the correct database name?</li><li>Have you entered the correct username and password?</li><li>Have you entered the correct database hostname?</li></ul>', array('%error' => $e->getMessage())));
									return FALSE;
								}
								return TRUE;
							}

							/**
							 * Run SQL tests to ensure the database can execute commands with the current user.
							 */
							protected function runTestQuery($query, $pass, $fail, $fatal = FALSE) {
								try {
									db_query($query);
									$this->pass(st($pass));
								}
								catch (Exception $e) {
									$this->fail(st($fail, array('%query' => $query, '%error' => $e->getMessage(), '%name' => $this->name())));
									return !$fatal;
								}
							}

							/**
							 * Check the engine version.
							 */
							protected function checkEngineVersion() {
								if ($this->minimumVersion() && version_compare(Database::getConnection()->version(), $this->minimumVersion(), '<')) {
									$this->fail(st("The database version %version is less than the minimum required version %minimum_version.", array('%version' => Database::getConnection()->version(), '%minimum_version' => $this->minimumVersion())));
								}
							}

							/**
							 * Return driver specific configuration options.
							 *
							 * @param $database
							 *  An array of driver specific configuration options.
							 *
							 * @return
							 *   The options form array.
							 */
							public function getFormOptions($database) {
								$form['database'] = array(
										'#type' => 'textfield',
										'#title' => st('Database name'),
										'#default_value' => empty($database['database']) ? '' : $database['database'],
										'#size' => 45,
										'#required' => TRUE,
										'#description' => st('The name of the database your @drupal data will be stored in. It must exist on your server before @drupal can be installed.', array('@drupal' => drupal_install_profile_distribution_name())),
								);

								$form['username'] = array(
										'#type' => 'textfield',
										'#title' => st('Database username'),
										'#default_value' => empty($database['username']) ? '' : $database['username'],
										'#required' => TRUE,
										'#size' => 45,
								);

								$form['password'] = array(
										'#type' => 'password',
										'#title' => st('Database password'),
										'#default_value' => empty($database['password']) ? '' : $database['password'],
										'#required' => FALSE,
										'#size' => 45,
								);

								$form['advanced_options'] = array(
										'#type' => 'fieldset',
										'#title' => st('Advanced options'),
										'#collapsible' => TRUE,
										'#collapsed' => TRUE,
										'#description' => st("These options are only necessary for some sites. If you're not sure what you should enter here, leave the default settings or check with your hosting provider."),
										'#weight' => 10,
								);

								$profile = drupal_get_profile();
								$db_prefix = ($profile == 'standard') ? 'drupal_' : $profile . '_';
								$form['advanced_options']['db_prefix'] = array(
										'#type' => 'textfield',
										'#title' => st('Table prefix'),
										'#default_value' => '',
										'#size' => 45,
										'#description' => st('If more than one application will be sharing this database, enter a table prefix such as %prefix for your @drupal site here.', array('@drupal' => drupal_install_profile_distribution_name(), '%prefix' => $db_prefix)),
										'#weight' => 10,
								);

								$form['advanced_options']['host'] = array(
										'#type' => 'textfield',
										'#title' => st('Database host'),
										'#default_value' => empty($database['host']) ? 'localhost' : $database['host'],
										'#size' => 45,
										// Hostnames can be 255 characters long.
										'#maxlength' => 255,
										'#required' => TRUE,
										'#description' => st('If your database is located on a different server, change this.'),
								);

								$form['advanced_options']['port'] = array(
										'#type' => 'textfield',
										'#title' => st('Database port'),
										'#default_value' => empty($database['port']) ? '' : $database['port'],
										'#size' => 45,
										// The maximum port number is 65536, 5 digits.
										'#maxlength' => 5,
										'#description' => st('If your database server is listening to a non-standard port, enter its number.'),
								);

								return $form;
							}

							/**
							 * Validates driver specific configuration settings.
							 *
							 * Checks to ensure correct basic database settings and that a proper
							 * connection to the database can be established.
							 *
							 * @param $database
							 *   An array of driver specific configuration options.
							 *
							 * @return
							 *   An array of driver configuration errors, keyed by form element name.
							 */
							public function validateDatabaseSettings($database) {
								$errors = array();

								// Verify the table prefix.
								if (!empty($database['prefix']) && is_string($database['prefix']) && !preg_match('/^[A-Za-z0-9_.]+$/', $database['prefix'])) {
									$errors[$database['driver'] . '][advanced_options][db_prefix'] = st('The database table prefix you have entered, %prefix, is invalid. The table prefix can only contain alphanumeric characters, periods, or underscores.', array('%prefix' => $database['prefix']));
								}

								// Verify the database port.
								if (!empty($database['port']) && !is_numeric($database['port'])) {
									$errors[$database['driver'] . '][advanced_options][port'] =  st('Database port must be a number.');
								}

								return $errors;
							}

}

/**
 * Exception thrown if the database installer fails.
 */
class DatabaseTaskException extends Exception {
}

/**
 * Replace values in settings.php with values in the submitted array.
 *
 * @param $settings
 *   An array of settings that need to be updated.
 */
function drupal_rewrite_settings($settings = array(), $prefix = '') {
	$default_settings = 'sites/default/default.settings.php';
	drupal_static_reset('conf_path');
	$settings_file = conf_path(FALSE) . '/' . $prefix . 'settings.php';

	// Build list of setting names and insert the values into the global namespace.
	$keys = array();
	foreach ($settings as $setting => $data) {
		$GLOBALS[$setting] = $data['value'];
		$keys[] = $setting;
	}

	$buffer = NULL;
	$first = TRUE;
	if ($fp = fopen(DRUPAL_ROOT . '/' . $default_settings, 'r')) {
		// Step line by line through settings.php.
		while (!feof($fp)) {
			$line = fgets($fp);
			if ($first && substr($line, 0, 5) != '<?php') {
				$buffer = "<?php\n\n";
			}
			$first = FALSE;
			// Check for constants.
			if (substr($line, 0, 7) == 'define(') {
				preg_match('/define\(\s*[\'"]([A-Z_-]+)[\'"]\s*,(.*?)\);/', $line, $variable);
				if (in_array($variable[1], $keys)) {
					$setting = $settings[$variable[1]];
					$buffer .= str_replace($variable[2], " '" . $setting['value'] . "'", $line);
					unset($settings[$variable[1]]);
					unset($settings[$variable[2]]);
				}
				else {
					$buffer .= $line;
				}
			}
			// Check for variables.
			elseif (substr($line, 0, 1) == '$') {
				preg_match('/\$([^ ]*) /', $line, $variable);
				if (in_array($variable[1], $keys)) {
					// Write new value to settings.php in the following format:
					//    $'setting' = 'value'; // 'comment'
					$setting = $settings[$variable[1]];
					$buffer .= '$' . $variable[1] . " = " . var_export($setting['value'], TRUE) . ";" . (!empty($setting['comment']) ? ' // ' . $setting['comment'] . "\n" : "\n");
					unset($settings[$variable[1]]);
				}
				else {
					$buffer .= $line;
				}
			}
			else {
				$buffer .= $line;
			}
		}
		fclose($fp);

		// Add required settings that were missing from settings.php.
		foreach ($settings as $setting => $data) {
			if ($data['required']) {
				$buffer .= "\$$setting = " . var_export($data['value'], TRUE) . ";\n";
			}
		}

		$fp = fopen(DRUPAL_ROOT . '/' . $settings_file, 'w');
		if ($fp && fwrite($fp, $buffer) === FALSE) {
			throw new Exception(st('Failed to modify %settings. Verify the file permissions.', array('%settings' => $settings_file)));
		}
	}
	else {
		throw new Exception(st('Failed to open %settings. Verify the file permissions.', array('%settings' => $default_settings)));
	}
}

/**
 * Verify an install profile for installation.
 *
 * @param $install_state
 *   An array of information about the current installation state.
 * @return
 *   The list of modules to install.
 */
function drupal_verify_profile($install_state) {
	$profile = $install_state['parameters']['profile'];
	$locale = $install_state['parameters']['locale'];

	include_once DRUPAL_ROOT . '/includes/file.inc';
	include_once DRUPAL_ROOT . '/includes/common.inc';

	$profile_file = DRUPAL_ROOT . "/profiles/$profile/$profile.profile";

	if (!isset($profile) || !file_exists($profile_file)) {
		throw new Exception(install_no_profile_error());
	}
	$info = $install_state['profile_info'];

	// Get a list of modules that exist in Drupal's assorted subdirectories.
	$present_modules = array();
	foreach (drupal_system_listing('/^' . DRUPAL_PHP_FUNCTION_PATTERN . '\.module$/', 'modules', 'name', 0) as $present_module) {
		$present_modules[] = $present_module->name;
	}

	// The install profile is also a module, which needs to be installed after all the other dependencies
	// have been installed.
	$present_modules[] = drupal_get_profile();

	// Verify that all of the profile's required modules are present.
	$missing_modules = array_diff($info['dependencies'], $present_modules);

	$requirements = array();

	if (count($missing_modules)) {
		$modules = array();
		foreach ($missing_modules as $module) {
			$modules[] = '<span class="admin-missing">' . drupal_ucfirst($module) . '</span>';
		}
		$requirements['required_modules'] = array(
				'title'       => st('Required modules'),
				'value'       => st('Required modules not found.'),
				'severity'    => REQUIREMENT_ERROR,
				'description' => st('The following modules are required but were not found. Move them into the appropriate modules subdirectory, such as <em>sites/all/modules</em>. Missing modules: !modules', array('!modules' => implode(', ', $modules))),
		);
	}
	return $requirements;
}

/**
 * Callback to install the system module.
 *
 * Separated from the installation of other modules so core system
 * functions can be made available while other modules are installed.
 */
function drupal_install_system() {
	$system_path = drupal_get_path('module', 'system');
	require_once DRUPAL_ROOT . '/' . $system_path . '/system.install';
	module_invoke('system', 'install');

	$system_versions = drupal_get_schema_versions('system');
	$system_version = $system_versions ? max($system_versions) : SCHEMA_INSTALLED;
	db_insert('system')
	->fields(array('filename', 'name', 'type', 'owner', 'status', 'schema_version', 'bootstrap'))
	->values(array(
			'filename' => $system_path . '/system.module',
			'name' => 'system',
			'type' => 'module',
			'owner' => '',
			'status' => 1,
			'schema_version' => $system_version,
			'bootstrap' => 0,
	))
	->execute();
	system_rebuild_module_data();
}

/**
 * Uninstalls a given list of modules.
 *
 * @param $module_list
 *   The modules to uninstall.
 * @param $uninstall_dependents
 *   If TRUE, the function will check that all modules which depend on the
 *   passed-in module list either are already uninstalled or contained in the
 *   list, and it will ensure that the modules are uninstalled in the correct
 *   order. This incurs a significant performance cost, so use FALSE if you
 *   know $module_list is already complete and in the correct order.
 *
 * @return
 *   FALSE if one or more dependent modules are missing from the list, TRUE
 *   otherwise.
 */
function drupal_uninstall_modules($module_list = array(), $uninstall_dependents = TRUE) {
	if ($uninstall_dependents) {
		// Get all module data so we can find dependents and sort.
		$module_data = system_rebuild_module_data();
		// Create an associative array with weights as values.
		$module_list = array_flip(array_values($module_list));

		$profile = drupal_get_profile();
		while (list($module) = each($module_list)) {
			if (!isset($module_data[$module]) || drupal_get_installed_schema_version($module) == SCHEMA_UNINSTALLED) {
				// This module doesn't exist or is already uninstalled, skip it.
				unset($module_list[$module]);
				continue;
			}
			$module_list[$module] = $module_data[$module]->sort;

			// If the module has any dependents which are not already uninstalled and
			// not included in the passed-in list, abort. It is not safe to uninstall
			// them automatically because uninstalling a module is a destructive
			// operation.
			foreach (array_keys($module_data[$module]->required_by) as $dependent) {
				if (!isset($module_list[$dependent]) && drupal_get_installed_schema_version($dependent) != SCHEMA_UNINSTALLED && $dependent != $profile) {
					return FALSE;
				}
			}
		}

		// Sort the module list by pre-calculated weights.
		asort($module_list);
		$module_list = array_keys($module_list);
	}

	foreach ($module_list as $module) {
		// Uninstall the module.
		module_load_install($module);
		module_invoke($module, 'uninstall');
		drupal_uninstall_schema($module);

		watchdog('system', '%module module uninstalled.', array('%module' => $module), WATCHDOG_INFO);
		drupal_set_installed_schema_version($module, SCHEMA_UNINSTALLED);
	}

	if (!empty($module_list)) {
		// Call hook_module_uninstall to let other modules act
		module_invoke_all('modules_uninstalled', $module_list);
	}

	return TRUE;
}

/**
 * Verify the state of the specified file.
 *
 * @param $file
 *   The file to check for.
 * @param $mask
 *   An optional bitmask created from various FILE_* constants.
 * @param $type
 *   The type of file. Can be file (default), dir, or link.
 * @return
 *   TRUE on success or FALSE on failure. A message is set for the latter.
 */
function drupal_verify_install_file($file, $mask = NULL, $type = 'file') {
	$return = TRUE;
	// Check for files that shouldn't be there.
	if (isset($mask) && ($mask & FILE_NOT_EXIST) && file_exists($file)) {
		return FALSE;
	}
	// Verify that the file is the type of file it is supposed to be.
	if (isset($type) && file_exists($file)) {
		$check = 'is_' . $type;
		if (!function_exists($check) || !$check($file)) {
			$return = FALSE;
		}
	}

	// Verify file permissions.
	if (isset($mask)) {
		$masks = array(FILE_EXIST, FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);
		foreach ($masks as $current_mask) {
			if ($mask & $current_mask) {
				switch ($current_mask) {
					case FILE_EXIST:
						if (!file_exists($file)) {
							if ($type == 'dir') {
								drupal_install_mkdir($file, $mask);
							}
							if (!file_exists($file)) {
								$return = FALSE;
							}
						}
						break;
					case FILE_READABLE:
						if (!is_readable($file) && !drupal_install_fix_file($file, $mask)) {
							$return = FALSE;
						}
						break;
					case FILE_WRITABLE:
						if (!is_writable($file) && !drupal_install_fix_file($file, $mask)) {
							$return = FALSE;
						}
						break;
					case FILE_EXECUTABLE:
						if (!is_executable($file) && !drupal_install_fix_file($file, $mask)) {
							$return = FALSE;
						}
						break;
					case FILE_NOT_READABLE:
						if (is_readable($file) && !drupal_install_fix_file($file, $mask)) {
							$return = FALSE;
						}
						break;
					case FILE_NOT_WRITABLE:
						if (is_writable($file) && !drupal_install_fix_file($file, $mask)) {
							$return = FALSE;
						}
						break;
					case FILE_NOT_EXECUTABLE:
						if (is_executable($file) && !drupal_install_fix_file($file, $mask)) {
							$return = FALSE;
						}
						break;
				}
			}
		}
	}
	return $return;
}

/**
 * Create a directory with specified permissions.
 *
 * @param $file
 *  The name of the directory to create;
 * @param $mask
 *  The permissions of the directory to create.
 * @param $message
 *  (optional) Whether to output messages. Defaults to TRUE.
 * @return
 *  TRUE/FALSE whether or not the directory was successfully created.
 */
function drupal_install_mkdir($file, $mask, $message = TRUE) {
	$mod = 0;
	$masks = array(FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);
	foreach ($masks as $m) {
		if ($mask & $m) {
			switch ($m) {
				case FILE_READABLE:
					$mod |= 0444;
					break;
				case FILE_WRITABLE:
					$mod |= 0222;
					break;
				case FILE_EXECUTABLE:
					$mod |= 0111;
					break;
			}
		}
	}

	if (@drupal_mkdir($file, $mod)) {
		return TRUE;
	}
	else {
		return FALSE;
	}
}

/**
 * Attempt to fix file permissions.
 *
 * The general approach here is that, because we do not know the security
 * setup of the webserver, we apply our permission changes to all three
 * digits of the file permission (i.e. user, group and all).
 *
 * To ensure that the values behave as expected (and numbers don't carry
 * from one digit to the next) we do the calculation on the octal value
 * using bitwise operations. This lets us remove, for example, 0222 from
 * 0700 and get the correct value of 0500.
 *
 * @param $file
 *  The name of the file with permissions to fix.
 * @param $mask
 *  The desired permissions for the file.
 * @param $message
 *  (optional) Whether to output messages. Defaults to TRUE.
 * @return
 *  TRUE/FALSE whether or not we were able to fix the file's permissions.
 */
function drupal_install_fix_file($file, $mask, $message = TRUE) {
	// If $file does not exist, fileperms() issues a PHP warning.
	if (!file_exists($file)) {
		return FALSE;
	}

	$mod = fileperms($file) & 0777;
	$masks = array(FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);

	// FILE_READABLE, FILE_WRITABLE, and FILE_EXECUTABLE permission strings
	// can theoretically be 0400, 0200, and 0100 respectively, but to be safe
	// we set all three access types in case the administrator intends to
	// change the owner of settings.php after installation.
	foreach ($masks as $m) {
		if ($mask & $m) {
			switch ($m) {
				case FILE_READABLE:
					if (!is_readable($file)) {
						$mod |= 0444;
					}
					break;
				case FILE_WRITABLE:
					if (!is_writable($file)) {
						$mod |= 0222;
					}
					break;
				case FILE_EXECUTABLE:
					if (!is_executable($file)) {
						$mod |= 0111;
					}
					break;
				case FILE_NOT_READABLE:
					if (is_readable($file)) {
						$mod &= ~0444;
					}
					break;
				case FILE_NOT_WRITABLE:
					if (is_writable($file)) {
						$mod &= ~0222;
					}
					break;
				case FILE_NOT_EXECUTABLE:
					if (is_executable($file)) {
						$mod &= ~0111;
					}
					break;
			}
		}
	}

	// chmod() will work if the web server is running as owner of the file.
	// If PHP safe_mode is enabled the currently executing script must also
	// have the same owner.
	if (@chmod($file, $mod)) {
		return TRUE;
	}
	else {
		return FALSE;
	}
}

/**
 * Send the user to a different installer page.
 *
 * This issues an on-site HTTP redirect. Messages (and errors) are erased.
 *
 * @param $path
 *   An installer path.
 */
function install_goto($path) {
	global $base_url;
	include_once DRUPAL_ROOT . '/includes/common.inc';
	header('Location: ' . $base_url . '/' . $path);
	header('Cache-Control: no-cache'); // Not a permanent redirect.
	drupal_exit();
}

/**
 * Returns the URL of the current script, with modified query parameters.
 *
 * This function can be called by low-level scripts (such as install.php and
 * update.php) and returns the URL of the current script. Existing query
 * parameters are preserved by default, but new ones can optionally be merged
 * in.
 *
 * This function is used when the script must maintain certain query parameters
 * over multiple page requests in order to work correctly. In such cases (for
 * example, update.php, which requires the 'continue=1' parameter to remain in
 * the URL throughout the update process if there are any requirement warnings
 * that need to be bypassed), using this function to generate the URL for links
 * to the next steps of the script ensures that the links will work correctly.
 *
 * @param $query
 *   (optional) An array of query parameters to merge in to the existing ones.
 *
 * @return
 *   The URL of the current script, with query parameters modified by the
 *   passed-in $query. The URL is not sanitized, so it still needs to be run
 *   through check_url() if it will be used as an HTML attribute value.
 *
 * @see drupal_requirements_url()
 */
function drupal_current_script_url($query = array()) {
	$uri = $_SERVER['SCRIPT_NAME'];
	$query = array_merge(drupal_get_query_parameters(), $query);
	if (!empty($query)) {
		$uri .= '?' . drupal_http_build_query($query);
	}
	return $uri;
}

/**
 * Returns a URL for proceeding to the next page after a requirements problem.
 *
 * This function can be called by low-level scripts (such as install.php and
 * update.php) and returns a URL that can be used to attempt to proceed to the
 * next step of the script.
 *
 * @param $severity
 *   The severity of the requirements problem, as returned by
 *   drupal_requirements_severity().
 *
 * @return
 *   A URL for attempting to proceed to the next step of the script. The URL is
 *   not sanitized, so it still needs to be run through check_url() if it will
 *   be used as an HTML attribute value.
 *
 * @see drupal_current_script_url()
 */
function drupal_requirements_url($severity) {
	$query = array();
	// If there are no errors, only warnings, append 'continue=1' to the URL so
	// the user can bypass this screen on the next page load.
	if ($severity == REQUIREMENT_WARNING) {
		$query['continue'] = 1;
	}
	return drupal_current_script_url($query);
}

/**
 * Functional equivalent of t(), used when some systems are not available.
 *
 * Used during the install process, when database, theme, and localization
 * system is possibly not yet available.
 *
 * Use t() if your code will never run during the Drupal installation phase.
 * Use st() if your code will only run during installation and never any other
 * time. Use get_t() if your code could run in either circumstance.
 *
 * @see t()
 * @see get_t()
 * @ingroup sanitization
 */
function st($string, array $args = array(), array $options = array()) {
	static $locale_strings = NULL;
	global $install_state;

	if (empty($options['context'])) {
		$options['context'] = '';
	}

	if (!isset($locale_strings)) {
		$locale_strings = array();
		if (isset($install_state['parameters']['profile']) && isset($install_state['parameters']['locale'])) {
			// If the given locale was selected, there should be at least one .po file
			// with its name ending in {$install_state['parameters']['locale']}.po
			// This might or might not be the entire filename. It is also possible
			// that multiple files end with the same extension, even if unlikely.
			$po_files = file_scan_directory('./profiles/' . $install_state['parameters']['profile'] . '/translations', '/'. $install_state['parameters']['locale'] .'\.po$/', array('recurse' => FALSE));
			if (count($po_files)) {
				require_once DRUPAL_ROOT . '/includes/locale.inc';
				foreach ($po_files as $po_file) {
					_locale_import_read_po('mem-store', $po_file);
				}
				$locale_strings = _locale_import_one_string('mem-report');
			}
		}
	}

	require_once DRUPAL_ROOT . '/includes/theme.inc';
	// Transform arguments before inserting them
	foreach ($args as $key => $value) {
		switch ($key[0]) {
			// Escaped only
			case '@':
				$args[$key] = check_plain($value);
				break;
				// Escaped and placeholder
			case '%':
			default:
				$args[$key] = '<em>' . check_plain($value) . '</em>';
				break;
				// Pass-through
			case '!':
		}
	}
	return strtr((!empty($locale_strings[$options['context']][$string]) ? $locale_strings[$options['context']][$string] : $string), $args);
}

/**
 * Check an install profile's requirements.
 *
 * @param $profile
 *   Name of install profile to check.
 * @return
 *   Array of the install profile's requirements.
 */
function drupal_check_profile($profile) {
	include_once DRUPAL_ROOT . '/includes/file.inc';

	$profile_file = DRUPAL_ROOT . "/profiles/$profile/$profile.profile";

	if (!isset($profile) || !file_exists($profile_file)) {
		throw new Exception(install_no_profile_error());
	}

	$info = install_profile_info($profile);

	// Collect requirement testing results.
	$requirements = array();
	foreach ($info['dependencies'] as $module) {
		module_load_install($module);
		$function = $module . '_requirements';
		if (function_exists($function)) {
			$requirements = array_merge($requirements, $function('install'));
		}
	}
	return $requirements;
}

/**
 * Extract highest severity from requirements array.
 *
 * @param $requirements
 *   An array of requirements, in the same format as is returned by
 *   hook_requirements().
 * @return
 *   The highest severity in the array.
 */
function drupal_requirements_severity(&$requirements) {
	$severity = REQUIREMENT_OK;
	foreach ($requirements as $requirement) {
		if (isset($requirement['severity'])) {
			$severity = max($severity, $requirement['severity']);
		}
	}
	return $severity;
}

/**
 * Check a module's requirements.
 *
 * @param $module
 *   Machine name of module to check.
 * @return
 *   TRUE/FALSE depending on the requirements are in place.
 */
function drupal_check_module($module) {
	module_load_install($module);
	if (module_hook($module, 'requirements')) {
		// Check requirements
		$requirements = module_invoke($module, 'requirements', 'install');
		if (is_array($requirements) && drupal_requirements_severity($requirements) == REQUIREMENT_ERROR) {
			// Print any error messages
			foreach ($requirements as $requirement) {
				if (isset($requirement['severity']) && $requirement['severity'] == REQUIREMENT_ERROR) {
					$message = $requirement['description'];
					if (isset($requirement['value']) && $requirement['value']) {
						$message .= ' (' . t('Currently using !item !version', array('!item' => $requirement['title'], '!version' => $requirement['value'])) . ')';
					}
					drupal_set_message($message, 'error');
				}
			}
			return FALSE;
		}
	}
	return TRUE;
}

/**
 * Retrieve info about an install profile from its .info file.
 *
 * The information stored in a profile .info file is similar to that stored in
 * a normal Drupal module .info file. For example:
 * - name: The real name of the install profile for display purposes.
 * - description: A brief description of the profile.
 * - dependencies: An array of shortnames of other modules this install profile requires.
 *
 * Additional, less commonly-used information that can appear in a profile.info
 * file but not in a normal Drupal module .info file includes:
 * - distribution_name: The name of the Drupal distribution that is being
 *   installed, to be shown throughout the installation process. Defaults to
 *   'Drupal'.
 *
 * Note that this function does an expensive file system scan to get info file
 * information for dependencies. If you only need information from the info
 * file itself, use system_get_info().
 *
 * Example of .info file:
 * @code
 *    name = Minimal
 *    description = Start fresh, with only a few modules enabled.
 *    dependencies[] = block
 *    dependencies[] = dblog
 * @endcode
 *
 * @param $profile
 *   Name of profile.
 * @param $locale
 *   Name of locale used (if any).
 *
 * @return
 *   The info array.
 */
function install_profile_info($profile, $locale = 'en') {
	$cache = &drupal_static(__FUNCTION__, array());

	if (!isset($cache[$profile])) {
		// Set defaults for module info.
		$defaults = array(
				'dependencies' => array(),
				'description' => '',
				'distribution_name' => 'Drupal',
				'version' => NULL,
				'hidden' => FALSE,
				'php' => DRUPAL_MINIMUM_PHP,
		);
		$info = drupal_parse_info_file("profiles/$profile/$profile.info") + $defaults;
		$info['dependencies'] = array_unique(array_merge(
				drupal_required_modules(),
				$info['dependencies'],
				($locale != 'en' && !empty($locale) ? array('locale') : array()))
		);

		// drupal_required_modules() includes the current profile as a dependency.
		// Since a module can't depend on itself we remove that element of the array.
		array_shift($info['dependencies']);

		$cache[$profile] = $info;
	}
	return $cache[$profile];
}

/**
 * Ensures the environment for a Drupal database on a predefined connection.
 *
 * This will run tasks that check that Drupal can perform all of the functions
 * on a database, that Drupal needs. Tasks include simple checks like CREATE
 * TABLE to database specific functions like stored procedures and client
 * encoding.
 */
function db_run_tasks($driver) {
	db_installer_object($driver)->runTasks();
	return TRUE;
}

/**
 * Returns a database installer object.
 *
 * @param $driver
 *   The name of the driver.
 */
function db_installer_object($driver) {
	Database::loadDriverFile($driver, array('install.inc'));
	$task_class = 'DatabaseTasks_' . $driver;
	return new $task_class();
}
